> Much of the argument for the existence of systemic biases comes from willful, repeated ignoring of the already extant evidence for nature/nurture.

I feel it is important to point out that this is an important consideration with regards to sex, not race. There is evidence of sexual dimorphism and hormonal differences between the sexes worldwide, but as far as I know there are no such trends between races. From what I understand, genetic diversity differs more within the races than between them.